Gas burner control



Aug. 20, 1935. SHAWN 2,011,779"

GAS BURNER CONTROL Original Filed Nov. 6, 1931 2 Sheets-Sheet 1 @4271 I I I F ISL? fi LL; JP

| r i 1 g A I 1 I l I 1 l I I I I I i I I I I I I i I l I '"T l I l I Inventor:

George B. Shawn H is Attorney Aug. 20, 1935. GQB. SHAWN 2,011,779

GAS BURN ER CONTROL Original Filed Nov. 6, 1931 2 Sheets-Sheet 2 Ihventor: George 15. Shawn J95 WWW/249W His Attorne g.

V or some part of Patented Aug. 20, 1935 at T 2,011,??9 I E Y new mesne assignments, to General Electric Company, a corporation of New York Original application November 6,1931, Serial No.

573,?90. Divided and this application March 27, 1934, Serial'No. 717,544

v r l 5 Claims. This application is a division of application, Serial No. 573,390, n'owPatent No. 1,956,136, filed November 6, 1931, for Service resumption mechanism.

The present application relates to an improved valve control system, particularly the improved valve control system for gas fired boilers in house heating service in which two three-way pilot valves, each operable automatically in accordance with predetermined conditions, jointly control the operation of the main gas burner snap action diaphragm valve to oneposition'and sepa rately control the operation thereof to another position as disclosed in said parent application,

'-With this control system the house heating gas fired boiler is normally controlled automatically by means'of a snap action valve'of diaphragm or other type which in turn is controlled by a three-way pilot valve operated between heat.

on and heat of positions by electrical means such as electromagnets under the control of a room thermostat; In such a system when the room temperature is'high the three-way electromagnetic pilot valve isin the heat off position and the main burner snap action gas Valve is inclosed position. Then in case the current fails A V h the electrical equipment getsout of 1 order or the electromagnetic three-way pilot valve sticks so that when the room cools down and the electromagnet or other device should normally move the pilot valve to heat on position it fails to do so. Such a contingency is adequately taken care of by the service'resumption mechanism disclosed and claimed in said parent application which enables the three-way pilot valve, at the will of the operator, to be moved to its hca't'on position under the particular contingenciessuch as referred to. 7

These same contingencies referred to above are 'j'ust as likely to occur'whe'n theroom tem pera ture is low and themain burner snap action gas Valve is in the open position with the burners of the gas fired boiler'lighted and in' full oporation. Under such conditions, it is extremely dangerous to rely upon the householder or oper ator discovering the failure of the automatic tem perature control and manually operating the electromagnetic three-way pilot valve to the heat off position. i i

In order to automatically protect against such dangerous conditions in accordance with my pres ent invention, an independently operable three-. way pilot control valve is provided and interconnected in cooperating, relation with the room thermostat controlled electromagnetic three-way valve. This independently operable pilot valve. is arranged to be operated in response to any of the varying conditions in the boiler ordinarily utilized for the safety control thereof, such' as by adevice subject to water level in the boiler, to

the steam pressure of ture of the Water in one or more of the the boiler, to the temperathe boiler or to any other same or similar factors of boiler operation. The cooperating relation of the two three-way valves is such that the independently operable valve is able to supersede the control of' the electromagnetic three-way valve and independently effect operation of the main gas burner snap action diaphragmgas valve to the off position upon the occurrence of abnormal or dangerous conditions in the boiler.

Furthermore, the improved three-way pilot valve control system of the presentinvention results in a very rapid-response of the snap action diaphragm valve to both the open and the closed positions, thereby increasing the certainty as Well as the safety of control for the gas fired heating boiler. My improved control system also avoids the various difliculties encountered in the use of valve control systems employing bleeder orifices WhlCl'l inherently produce a relatively slow response of the snap action diaphragm valve.

1 In the drawings, Fig. Us a side elevation showing a hot water heating boiler equippedwith the invention, the main burner snap action gas valve being shown in section; Fig.2 is a sectional elevation somewhat diagrammatic, illustrating the electromagnetic control or'pilot three-way valve with the electrical operating mechanism therefor, and the room thermostat electric circuits; and Fig. 3 is a sectional diagram of the associated three-way control valves.

In the arrangement shown in the drawings, A indicates a gas fired boiler, theburners of which (not shown) are supplied'with gas coming from a supply main l through theusual pressure regulating valve 2, snap action valve 3, and hand cutoff valve 4. The snap action valve 3 is of common type, including the valve member 5 whose stemb is attached to and is operated by a diaphragm l in a casing 8, the lower chamber 9 of which is always in open communication with the pressure of the supply main I, and the upper chamber i l) of which serves as a control chamber, being connected for thatpurpose to a pipe ll.

Said pipe communicates with suitable control mechanism, which in the form shown includes an electromagnetically operated three-way pilot valve, generally indicated atl2, and a boiler controlling three-way valve generally indicated at l 3;. the lattervalve being actuated by any varying condition in the boiler ordinarily utilized 'for cording to the setting of the parts, valve 32 rises and wholly cuts off connection of the pilot and boiler control valves to the escapement burner by pipe 35 and under all circumstances causes flow of the main gas supply pressure to the upper chamber of the snap action valve, either by way of chambers I6, I8 and pipe H or by way of chamber l6, pipe 28, chamber 27, chamber 29, pipe 20, chamber l9, chamber l8 and pipe H, superseding the electromagnetic valve control and compelling the snap action valve to close and cut off the heat independently of the control of the electromagnetic valve I2.

If for any reason the current supply fails at a time when the pilot valve 2| is in its lower or heat on position, or if a part of the electrical equipment. such as a transformer supplying the leads Q5, 5c, of a part of the switch mechanism, fails when the pilot valve is in heat on position, or, should said valve stick and fail to move upon an energization of the lower magnet 25, then the room temperature thermostat 40 would be demanding heat ofi but the pilot control valve 21! would be in a position holding the snap action valve open and heat would continue to be supplied. Under such emergency circumstances the furnace will remain burning subject only to the safety control of the boiler provided by the boiler three way control valve l3, which will still act as before to cause the snap action valve to close when the temperature of the boiler water rises too high independently of the failure of the electromagnetic valve in the heat on position.

When the temperature of the boiler water decreases, the three-way valve I3 is returned to the position shown in Fig. 3. This results in quickly venting the gas pressure on the upper side of diaphragm l through pipe H, chambers 58 and I9 of valve l2, pipe 28 and chambers 29 and 39 of valve l3 to the escapement pipe 3|. The gas pressure below diaphragm then the main gas valve 5; p What I claim as new and desire to secure by Letters Patent in the United States is:

1. In'a gas burner control, the combination of a valve for controlling the flow of gas from a quickly opens supply line to the burner, a gas pressure responsive device for operating said valve, a control conduit for admitting gas pressure to and venting gas pressure from said pressure responsive device and a pair of independently operable three-way valves interconnected with said conduit to jointly controlv the venting of the gas pressure from said pressure responsive valve and separately control the admission of gas pressure thereto.

2. Control'm'echanism for a gas burner comprising a valve for controlling the flow of gas from the gas supply line to the burner, a gas pressure responsive diaphragm operatively connected to said valve, means for applying gas pressure to one side of said diaphragm for opening said valve, conduit'means for equalizing the gas pressureon the opposite sides of the diaphragm to close said valve and for venting pressure from the other side of said diaphragm to reopen said valve, and apair of independently operable three-way pilot valves interconnected with said conduit means to jointly control the venting of the gas pressure from saidother side of the diaphragm and separately control the admission of gas pressure thereto.

3. Control mechanism for a gas fired heating boiler comprising a main valve for controlling the flow of gas from a gas supply line to the burner, a pressure responsive diaphragm operatively connected with said valve, means for applying gas pressure to one side of said diaphragm to open said valve, and means for admitting gas pressure to and venting the pressure from the other side of said diaphragm including a pair of three-way valves each having a pressure port, a vent port, and an intermediate port, and interconnecting conduit means whereby the said valves jointly control the venting of the pressure from said other side of said diaphragm and separately control the admission of pressure to said other side of said diaphragm.

4. Control mechanism for gas burner comprising a main valve for controlling the flow of gas from a gas supply line to the burner, a pressure responsive diaphragm operatively connected with said valve,'conduit means for admitting gas under pressure from said supply line to one side of said diaphragm for opening said valve, and conduit means including a pair of three-way valves for admitting gas under pressure from said supply line to the other side of said diaphragm to equalize the pressures thereon and thereby effect closure of said valve and for venting the gas pressure from said other side of said diaphragm to efiect the reopening of said valve, said valves having a pressure admitting port, a pressure venting port, and an intermediate port with the pressure admitting port of each valve communicating with said gas supply line and with the intermediate port of one valve communicating with said other side of said diaphragm and the intermediate port of the other valve communicating with the pressure venting port of said one valve whereby said pair of valves jointly control the venting of the pressure from said other side of said diaphragm and separately control the admission of gas pressure thereto.

5. In a control system for a gas fired boiler,

the combination of a diaphragm operated main between the intermediate port and either said pressure admitting port or said pressure venting port, electromagnetic means for operating the movable valve member of one of said valves, a room thermostat for controlling said electromagnetic means responsive to a condition of the boiler for operating the other of said valves, conduit means connecting the pressure admitting ports of both of said valves with said gas supply lines, a conduit connecting the intermediate port of said electromagnetically operated valve with the other side of said diaphragm, and a conduit connecting the intermediate port of said other valve with the pressure venting portof said electromagnetically actuated valve,

GEORGE B. SHAWN. 

